Just for information: I plugged a 128MB Lexar JumpDrive into the USB port of a 2820Vn and it was not recognised at all; USB light did not come on, web interface reported no drive. Tried FAT and FAT32. Drive works OK when plugged into a Windows box. Router seems OK, recognises a 32MB FAT drive with no trouble. From this I infer that not all USB drives are supported, before debugging try another type.